In situ synthesis, physical and mechanical properties of ZrB2-ZrC-WB composites

In this study, two composition ZrB2-ZrC-WB composites were synthesized by reactive hot-pressing of Zr + B4C + WC powder mixtures at 1900 degrees C. The microstructure of the resulting composites was characterized by a combination of scanning electron microscopy and X-ray diffraction. It is seen that highly-dense ZrB2-ZrC-WB composites with a homogenous fine-microstructure were obtained after the sintering. The mechanical behavior of the composites was evaluated using by testing under four-point bend testing at room and high temperatures. The results show that the high-temperature strength of the ZrB2-ZrC-WB composites was substantially improved, compared to ZrB2-ZrC-based composites without WB. In addition, the elastic properties, electrical conductivity, hardness and fracture toughness of the composites were measured at room temperature. The results reveal that these properties were comparable to those of ZrB2-ZrC-based composites without WB.